As of the last posting, I've kind-of-played through
the initial parts of Clancy's story. Now it narrows
down to five AS-6 Kingfish against the CIWS and the
damage control of one carrier.
The AEGIS cruiser is shot dry, other SAMs had their
chance, jammers were activated, and chaff was fired,
to bring the strike down from the original 140 AS-6
to 30. Arbitrarily, the Nimitz got four of them (a
5th one gets decoyed by chaff, which the GURPS rules
already had used).
> Weapon Weight Volume Cost Power WPS VPS CPS TL
> AS-6 - - - neg. 8,800 176 $2,700,000 7
>
> Weapon Warhead Guid. Type Damage Spd. End. Max. Skill
> AS-6 SAPHE BARHMU cr. 6d*133(0.5) 1,250 425 531,250 21
> plus exp. 6d*5,743[12d]
* The Phalanx is a 20mm six-barrel gatling firing at
RoF 50-75. I believe this is not variable but rather
a difference in models, but I'm picking RoF 60 for
ease of calculations.
Weapon Weight Volume Cost Power WPS VPS CPS TL
20mm Gatling 300 6 $19,000 3.6 0.4 0.004 $6(1) 7
Ammo Type: (1) APDS.
Weap Ammo Malf. Type Damage SS Acc 1/2D Max RoF
20mm Gatling APDS ver. cr. 6d*5(2) 20 16 2,250 9,150 60*
I'm assuming a fully stabilized, universal mount in a
limited-traverse turret.
* Fire control is a TL7 C4 mainframe dedicated to C4 gunner
plus a C1 small computer running C1 targeting. That gives
skill 12.
* The CIWS has two radars, one for search and one for fire
control. I'm assuming that the fire control can track a
SM+2 missile at 5 miles (-22) in a heavy EW environment
(-4) for a nominal range of 70 miles. That would be a
350-lb. radar for targeting alone, but the multi-ton
weight of the system has to come from somewhere.
* The infrared system is a more recent addition.
* Any hit on the missile is a kill, and the chances of a
PD-based defense roll are too low to matter.
* If the CIWS had a turn for aiming, the roll to hit the
missile is
12 for skill
+ 12 for min(Acc, skill)
+ 2 for radar ranging
+ SM (3 for a Kingfish, 2 for lesser missiles)
- speed/range
At 1,250 yards and speed 1,250, the roll is 10.
At 2,500 yards, the roll is 9.
At 3,750 yards, the roll is 8.
To hit with one round out of the burst, it is enough to
fail the roll by -2, and there are 3 rolls per turn. So
the odds of scoring at no hit out of three turns of fire
are
0.5^3 * 0.375^3 * 0.259^3 = 0.011%, a near-certain kill,
but doing so occupied the Phalanx for four turns. Since
there are more incoming missiles than Phalanx units on
a carrier, better make it two or just one turn of fire.
One turn of aiming and one turn of fire would give a
kill probability of 87.5%.
* Clancy gave us two successful CIWS firings, one case of
a late miss by chaff (the Vehicles system made that one
roll upon entering the cloud), and two missiles not
engaged due to a software bug. Call it a crit failure.
* Even so, four simultaneous missiles from the same face
could have overloaded the CIWS of that arc. Assume two
Kingfish hit ...
There are two separate attacks, doing 6d*133(0.5) crushing
damage, average 2,793(0.5), followed by 6d*5,743 explosive
damage, average 120,603, and 12d cutting damage, repeated
12 times for a SM+12 target (VE190), average 504d.
* I don't know the DR of a modern carrier, but looking at
WWII for a gut feeling, it will be less than DR 1,400,
so the kinetic part of the attack goes through to turn
the remainder into an internal explosion.
* Under the basic vehicle damage rules, this will be some
15% of the body HP. (A hit on the superstructure would
bring that subassembly below 0 HP.)
* There is no chance of disabling the body, or flooding it
to any significant degree, even if the strikes were at
the waterline.
* The attack counts as a flame attack, so there will be two
fires. Starting the fire could only fail on attacks doing
less than 18 points of damage.
Each fire does 2d-4 per ten seconds. Forget that.
It will be critical if the carrier has a fire suppression
system or a fire extinguisher. Fire suppression would get
a roll to quench the fire immediately, and this roll is
certain to work since there will be more than one system
at work. A fire extinguisher is certain to work after 10
turns, which will be a critical difference ...
There are 0 or 10 rolls of 1d, and on a six 1d shots of
ammunition explode. With mere fire extinguishers, there
is an 84% chance of at least one ammunition explosion,
which would be a flame attack starting a separate fire
in its own right, with an average of 1.67 explosions
involving 5.83 weapons, so this could snowball ...
* Regardless of the firefighting gear, each of the Kingfish
did more than 5% of body HP in damage, so it will get an
1d roll which explodes ammo on a 5-6.
* If the exploding ammo are cannon rounds or AAMs, nothing
really bad will happen, but once the explosion involves
ordnance to the tune of 1,000-lb. bombs or worse, the
ammo explosion will exceed 5% of body HP itself.
Since there is only one check for ammo explosions under
this part of the rules, the effect will wind down.
* Assuming the vehicle designer did the smart thing under
the rules and mounted fire suppression, the strike from
two missiles should do somewhere between 15% and 25% of
body HP. That would mean a carrier can survive two or
even four Kingfish, but ten of them should sink it.
In the Clancy story, Foch and Saipan went down, and Nimitz
and Saratoga were battered.
There are some lessons for a 'rules-optimized' rather than
'historical' carrier in this:
* The Tomcats should have degraded the raid, but you can't
count on that. Even without a successful feint, they may
be away on an offensive mission.
* Another AEGIS would have helped. It was a three-carrier
battlegroup, after all.
* Four CIWS are not enough, and it should be simple to
find the space for eight or twelve.
* Proper fire suppression is critical. This is a case of
one bug in the system countering another -- fire is too
lethal and firefighting too easy.
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